Sti rear brakes:
http://www.zilvia.net/f/showpost.php...&postcount=237
Sti rear brembos fit over 300zx rear rotors thereby allowing you to retain the 300zx drum e-brake
The 300zx rotors are 2mm thinner than Sti rear rotors. Presumably you could just run normal sti pads or get something custom made, it shouldn't be too ridiculous for a pad company to give you an extra mm on each side to avoid problems.
if u want matching fronts...racingbrake already has 2pc rotors for the 350z brembo fronts, so you can either run the brembos from 350z or get the SPL or CosmoRacing adapter braket and use 30mm 3z brakes (which i'm doing, since they are way lighter calipers...and cheaper too)